Fluctuations in the formation time of ultracold dimers from fermionic atoms

TL;DR

This paper studies the quantum and classical fluctuations in the timing of ultracold dimer formation from fermionic atoms, revealing significant initial fluctuations and contrasting behaviors in dissociation processes.

Contribution

It introduces a heuristic classical stochastic model that qualitatively matches quantum results and analyzes the impact of atomic energy non-degeneracy on fluctuations.

Findings

Large passage time fluctuations due to quantum initial state fluctuations

Classical model agrees qualitatively with quantum dynamics in early stages

Dissociation from bosonic dimers shows minimal passage time fluctuations

Abstract

We investigate the temporal fluctuations characteristic of the formation of molecular dimers from ultracold fermionic atoms via Raman photoassociation. The quantum fluctuations inherent to the initial atomic state result in large fluctuations in the passage time from atoms to molecules. Assuming degeneracy of kinetic energies of atoms in the strong coupling limit we find that a heuristic classical stochastic model yields qualitative agreement with the full quantum treatment in the initial stages of the dynamics. We also show that in contrast to the association of atoms into dimers, the reverse process of dissociation from a condensate of bosonic dimers exhibits little passage time fluctuations. Finally we explore effects due to the non-degeneracy of atomic kinetic energies.